Question

For the following system, if you isolated y in the first equation to use the Substitution Method, what expression would you substitute into the second equation?

4x - y = 8
2x + 3y = 9
Answer
-8 + 4x
8 + 4x
-8 - 4x
8 - 4x

Answer 1

-8+4x

Answer 2

to isolate y in
4x - y = 8
we get y by itsself, so we move the 4x term over to the other side by subtracting it from both sides, now we have
-y = -4x + 8
divide or multiply by negative 1 to get rid of the negative sign and get
y = 4x - 8
now plug that into the other one
2x + 3y = 9
like this
2x + 3(4x - 8) = 9
Distribute
2x + 12x - 24 = 9
14x = 33
x = 33/14